1. Field of the Invention
This invention relates to a process of providing in a liquid-containing liquid friction coupling an air-filled space having a predetermined volume.
2. Description of the Prior Art
Mass-produced liquid friction couplings of a given series are desired to have the same characteristics regarding the dependence of the transmitted torque on the speed difference. But the family of characteristic curves of a given coupling will primarily depend on the volume of the air-filled space in the liquid friction coupling and owing to the inevitable manufacturing tolerances the volume of that air-filled space differs from coupling to coupling so that different couplings of a series usually have different characteristic curves.
It is known in practice to record the characteristics of each coupling of a series while the coupling is installed on a test stand and to compare the recorded characteristic curves with the desired curves. In dependence on the result of that comparison, liquid is then removed from or added to the coupling until another test reveals that the family of characteristic curves closely match the desired curves. That procedure requires complicated and timeconsuming manipulations, particularly because it is often necessary to operate the coupling on the test stand repeatedly and because the coupling must be cooled after each test operation.